As the liquid crystal display technologies continue to advance, the three-dimensional (3D) display technology has obtained significant attention. One basic principle of three-dimensional display technologies is that left and right human eyes receive different pictures, then the human brain overlays the image information from these different pictures, and reconstruct to obtain a vision of three-dimensional effect.
A layer of naked-eye 3D grating may be added onto a display in order to achieve three-dimensional display. Based on implementation manners, generally naked-eye 3D gratings are classified into column lens grating and slit grating, both of which can be realized using liquid crystal gratings. For example, the liquid crystal grating as illustrated in FIG. 1 is generally composed of an upper polarizer sheet 1, a lower polarizer sheet 2, an upper substrate 3, a lower substrate 4, and a liquid crystal layer 5 arranged between the two substrates. The upper substrate 3 and the lower substrate 4 comprise a plate electrode 6 and strip electrodes 7 respectively, and the plurality of electrode strips of the strip electrodes 7 are arranged parallel to each other. The working principle for this liquid crystal grating is described as follows.
When potential difference is present between the strip electrodes 7 and the plate electrode 6 and thus an electric field is generated, the liquid crystal molecules corresponding to the strip electrodes 7 are subjected to rotation, while other liquid crystal molecules keep original shapes without any rotation. At this point, light enters through the lower polarizer sheet 2, and then polarized light parallel to the transmission axle of the lower polarizer sheet 2 enters the liquid crystal layer 5. The vibration direction of the polarized light varies gradually when passing though the rotated liquid crystal molecules, and upon reaching the upper polarizing plate 1, the vibration direction of the polarized light becomes inconsistent with the transmission axle of the upper polarizing plate 1, such that the light with changed vibration direction can not pass through the upper polarizing plate 1, and therefore dark strips are thereby formed in the zones corresponding to the strip electrodes. In contrast, the vibration direction of the polarized light does not vary when passing though non-rotated liquid crystal molecules, and upon reaching the upper polarizing plate 1, the vibration direction of the polarized light is consistent with the transmission axle of the upper polarizing plate 1, such that the light with unchanged vibration direction can pass through the upper polarizing plate 1, bright strips are thereby formed in the zones corresponding to parts other than the strip electrodes. In this way, a parallax grating in an extending direction along the length of the strip electrodes is formed, thus achieving a grating three-dimensional display mode. In a 3D mode, the parallax grating is controlled to allow that the light emitted from the pixels corresponding to left eye pictures can only enter a left eye while the light emitted from the pixels corresponding to right eye pictures can only enter a right eye, which makes it possible for the left and right eyes to catch pictures different from each other and thus achieves a three-dimensional display effect.
Along with growth of the touch display technologies recently, there appears a 3D display device incorporating a touch screen and a three-dimensional display, and the configuration thereof is to further add a layer of touch substrate on a three-dimensional display screen. However, such a configuration and its production processes are relatively complex, and increase overall costs for manufacturing modules, and at the same time, the thickness of the display is increased greatly since an additional layer for the touch substrate become necessary.